Field of the Invention
The subject invention relates to turbine blade vibration dampers, and more particularly to turbine blade dampers with coolant apertures.
Description of Related Art
Matefaces extend along the opposing edges of adjacent turbine blade platforms. Blade platform matefaces generally extend axially along the blade platform from the upstream (leading) edge of the blade to the downstream (trailing) edge of the blade. Blade platforms of adjacent turbine blades further define a mateface gap between the opposing matefaces. Since blades move in response to variation force applied to the blades airfoil by the combustion gases during operation, the mateface gap prevents opposed blade platforms from contact one another during operation. The turbine disk can also include turbine blade vibration dampers arranged beneath portions of adjacent blades and extending across the gap for purposes of stiffening the blade structures and reducing blade platform movement during engine operation.
Hot combustion gases transiting the mateface gap can damage the mateface edges of the blade platforms. For example, the hot gases can heat the platform material such that the mechanical properties of the material change, thereby weakening the blade structure. The gases can also remove material from the blade platform mateface edges. In extreme situations, hot combustion gases can erode or burn back the blade platform mateface. This can reduce engine efficiency and require that the engine be taken out of service so that the damaged blades can be replaced. Some turbine blades therefore include cooling channels extending through the structure for supplying coolant portions of the turbine otherwise vulnerable to damage from exposure to hot combustion gases.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is a continuing need to improve engine efficiency such as by reducing the amount of coolant necessary for blade platform mateface cooling. There is also a need for more uniform blade platform mateface cooling. There also remains a need for turbine blades and blade vibration dampers that are easy to make and use. The present invention provides solution to these and other needs in the art.